SharpCap Forums

Personally, I rarely bin with this camera so it likely won't affect me, but that doesn't mean it won't affect somebody else...

If you would like me to do some beta testing with various settings combinations, just let me know...

Hi,

I think I am getting closer to something that should work - I had to throw away my first go at this as it 'should have worked', but just broke everything else. I have had to introduce a 3 way option for overscan handling - 'classic sharpcap', 'include' and 'exclude' - the classic one keeps things the way they were before any of these changes.

RIght now, I think it would work as long as you dont try to change between live and still while using ROI. Need to work out a way around that that hopefully doesn't involve resetting the camera back to full ROI then back down again (as the ROI change and re-initialize is slow).

cheers,

Robin

Hi,

please give the very latest version a try when you have the chance - you should be able to get the full area by using the 'Include Overscan Area' in the camera settings page of the main SharpCap settings.

There is also 'try to exclude' as an option - that will use info from the SDK to try to cut the overscan area out while in still mode. I use 'try' because on the one sample I have, the SDK results for the area to use still leave a black border on the right and a glitched column near the left of the image, so I don't think the SDK always gives the right values to achieve excluding the overscan area.

Finally the 'classic sharpcap' option is the default. It's definitely not the 'right' area as it will use the size reported by the SDK with the overscan cut off, but not in the right offset in the full sensor area. However, that's what SharpCap did before, so for people who have already captured dark frames, using 'classic sharpcap' will mean that newly captured light frames will be compatible with the old darks...

cheers,

Robin

You appear to have resolved the QHY Overscan Riddle! Selecting the option to [Attempt to] Exclude Overscan Area gives me the slightly smaller image I have been getting from SharpCap, while Include Overscan Area gives me the full sensor resolution that I get in other imaging apps.

However (and this may affect other people more than me) the Classic Sharpcap Compatibility does something else; it appears to be removing the overscan area from the right and bottom edges, instead of the left and bottom, so I see a thin black area on the left edge that was not there before; I went back and reinstalled v14136 to confirm it.

Hi,

thanks for the feedback - I was expecting the behaviour of 'classic' and 'try to exclude' to be the other way around, as I thought that classic was the sending the same commands to the camera as I did before starting all these changes. I will go back and check that out

Anyway, glad to hear that you have access to the full area now!

cheers,

Robin

Hi,

OK, got it sorted now - the old code that 'classic' was supposed to be simulating always told the camera to ignore the overscan area, even if the camera claimed it couldn't do that. The new 'classic' code was checking for the overscan ignore support, finding that it was missing and not sending that message.

I now have 'bug for bug' compatibility between classic and the way that SharpCap used to work before I started tinkering with this. I think that in most cases it will mean that 'classic' and 'try to ignore overscan' work the same way, but I will keep both for now in case there are some cameras where they differ.

cheers,

Robin

Awesome; thanks Robin!

As a (now retired) programmer, I've had to keep a known bug in the code for backward compatibility at least once, too.

I can confirm that in ver 14185, your settings around the QHY overscan area handling now appear to work as expected. The only oddity I've seen is that sometimes (but not always) I have needed to restart SharpCap to get changing that selection to take effect. I have messed around with it a bit, but I haven't been able to reproduce it regularly enough to define just when that happens. Honestly, I don't think it's a bug worth chasing because most people will probably never change that setting once they have it the way they want it.

Thanks for all the hard work on this!

Hi,

glad we got there in the end

I would expect the change of the option to only work properly if you close then re-open the camera after changing it. If you change it while the camera is open then nothing will happen until you switch resolution/bit depth, and at that point you might get odd behaviour. Anyway, as you say, it's probably something that most people will change once, so it's not worth chasing up the case where SharpCap is not restarted or the camera is not closed/reopened.

cheers,

Robin